[Enhancement][PdfViewer] Introduce Pinch zoom functionality

[vveesseelliinnaa]

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• Suggestion for improvement

Current behavior

Currently pinching the PDF loaded in the PdfViewer zooms the whole component (including the Toolbar), while it will be useful to be able to pinch zoom in/out only the loaded content.
This feature is already available in the PdfJS library as of version v3.3.122 - mozilla/pdf.js#2582

Expected behavior

Only the content should be zoomed when pinching like in the following PDF.js demo - https://mozilla.github.io/pdf.js/web/viewer.html

Minimal reproduction of the problem with instructions

1. Open the following demo on mobile browser - https://y5cyw2.csb.app/
2. Try to zoom the content with pinching

Additional information

Requested in Ticket ID: 1644499
Internal issue - https://github.com/telerik/kendo-pdfviewer-common/issues/41